JPS6128959Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an end portion of an internally coated steel pipe.

(Prior art) Conventionally, when connecting internally coated steel pipes, in order to prevent corrosion of the end faces of the pipes, for example, as disclosed in Japanese Utility Model Publication No. 17969/1980, the internally coated steel pipes are connected closely by straddling the inner surface from the end face. A covering ring made of a heat-resistant or anti-corrosion thin plate having an L-shaped cross section is adhered with a heat-resistant or anti-corrosion adhesive, or a flange is provided at one end of the straight pipe part as in Japanese Utility Model Publication No. 51-51043. Using a flanged short pipe made of synthetic resin, the pipe wall of one end adjacent to the straight pipe part is bent inward along the circumferential direction of the straight pipe part, and a concave part is provided on the outer surface of the one end part of the straight pipe part. It may coat the ends of internally coated steel pipes.

(Problem to be solved by the invention) However, in all of the above cases, when the inner diameter of the inner-coated steel pipe varies, a covering ring with a straight pipe portion that matches the inner diameter or a short flange Since the end portion of the internally coated steel pipe must be coated using a pipe, there is a drawback that the work is complicated.

(Means for Solving the Problems) The pipe end of the internally coated steel pipe of the present invention is formed into an inclined surface whose diameter gradually increases as the inner circumferential surface of the pipe end of the steel pipe goes toward the opening edge. A corrosion-resistant annular body in which the tube end of an internally coated steel pipe whose inner circumferential surface and said inclined surface are coated with a thermoplastic resin or the like covers at least the tube end surface and said inclined surface which is coated with a thermoplastic resin or the like. It is crowned with

Example Hereinafter, the present invention will be explained with reference to embodiments of the drawings.

FIG. 1 is a partially cutaway perspective view showing an embodiment of the present invention. 1 is an inner-coated steel pipe, and steel pipe 11
The inner circumferential surface of the tube end is formed into an inclined surface 111 whose diameter gradually increases toward the opening edge, and a coating layer 12 such as a thermoplastic resin or a coating film is provided on the inner circumferential surface of the steel pipe 11, and the inclined surface The surface 111 is also coated to form an inclined surface 121 of the internally coated steel pipe 1.

Reference numeral 2 denotes a stainless steel annular body, in which a ring part 22 is provided at one end of a cylindrical part 21 having an inner diameter approximately equal to the outer diameter of the end of the internally coated steel pipe 1, and a ring part 22 is provided inwardly at the other end of the cylindrical body 21. An upright part 23 is provided to cover the end surface of the internally coated steel pipe 1, and a protruding piece 24 is provided inside the end of the upright part 23 and has an inclined part 241 corresponding to the inclined surface 121 of the internally coated steel pipe 1. It is. The annular body 2 is placed on the end of the internally coated steel pipe 1, the inner peripheral surface of the cylindrical part 21 is brought into contact with the outer peripheral surface of the end of the internally coated steel pipe 1, and the inner surface of the upright part 23 is brought into contact with the pipe end. The ring portion 22 is abutted and welded to the outer circumferential surface of the inner-coated steel pipe 1, forming an end portion of the inner-coated steel pipe.

FIG. 2 is a partially cutaway front view showing another embodiment of the present invention. 1' is an inner-coated steel pipe similar to that described in the embodiment of FIG. 2' is an annular body made of synthetic resin, which covers the end surface of the inner-coated steel pipe 1' inwardly at one end of the cylindrical part 21' having an inner diameter approximately equal to the outer diameter of the end of the inner-coated steel pipe 1'. An upright part 23' is provided, and a projecting piece 24' having an inclined part 241' corresponding to the inclined surface 121' of the inner-coated steel pipe 1 is provided inside the end of the upright part 23'.

An annular body 2' is attached to the end of the inner-coated steel pipe 1, and a cylindrical part 21' is attached to the outer peripheral surface of the end of the inner-coated steel pipe 1.
The inner circumferential surface of the upright portion 23' is bonded to the inner circumferential surface of the tube, the inner surface of the upright portion 23' is brought into contact with the tube end surface, and the inclined portion 241' is bonded to the inclined surface 121' of the inner circumferential surface, forming the tube end of the inner-coated steel tube. There is.

Incidentally, both the annular bodies 2 and 2' mentioned above are bottomless, and even if the annular bodies 2 and 2' are placed on the end of the pipe, it will not prevent water from flowing inside the pipe, and smooth flow will not be ensured. ing.

Next, the manner of use of the embodiment shown in FIG. 1 will be explained with reference to FIG. 3.

Reference numerals 1 and 1 indicate internally coated steel pipes, and annular bodies 2 and 2 are crowned at the ends of the pipes. Reference numeral 3 designates a pipe joint, in which pieces 32 protrude outward from both ends of the split housings 31, 31.
is provided, and a packing 33 is attached to the central inner peripheral surface of the split housings 31, 31, and the split housing 3
A concave groove 311 into which the ring portion 22 of the annular body 2 is inserted is provided along the circumferential direction on the inner circumferential surface of the end portion of the split housing 31 , and the split housings 31 , 31 can be fastened together by a fastener 34 .

The pipe ends of the internally coated steel pipe 1, the pipe ends of which are covered with the annular body 2, are made to face each other, and a packing 33 is placed thereon.
Cover and tighten the split housings 31, 31 with attached fittings 34, and with the ends of the inner-coated steel pipes 1, 1 covered with the annular bodies 2, 2, seal them watertight with the packing 33 using the pipe joint 3. Connected and used.

In addition, as shown in FIG. 4 for the embodiment shown in FIG. Cover the main body 31' of the pipe joint 3' on top, push the packing 33', 33' between the main body 31' and the annular plates 2', 2', hold them with the rings 34', 34', and remove the retaining rings 35', Tighten the main body 31' and the cap nuts 36', 36' so that the ends of the inner-coated steel pipes 1', 1' are covered with the annular bodies 2', 2'. The joint 3' may be used by connecting the packings 33', 33' in a watertight manner.

(Effect of the invention) The pipe end of the inner-coated steel pipe of the present invention is formed into an inclined surface whose diameter gradually increases as the inner peripheral surface of the pipe end goes toward the opening edge, and the inner peripheral surface of the steel pipe and the slope Since the end of an internally coated steel pipe whose surface is coated with thermoplastic resin or the like is covered with a corrosion-resistant annular body that covers at least the inclined surface and the pipe end face, the internal diameter of the internally coated steel pipe varies. However, since the inclined portion of the inner circumferential surface of the tube end and the tube end surface can be covered with the annular body, the tube end of the internally coated steel tube can be protected from corrosion.

Further, even if the end of the tube is covered with an annular body, water etc. can flow smoothly in the tube.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing one embodiment of the present invention, FIG. 2 is a partially cutaway perspective view showing another embodiment of the present invention, and FIG. 3 is a partially cutaway perspective view of the embodiment of the present invention. FIG. 4 is a partially cutaway front view illustrating how the embodiment of FIG. 2 is used. Explanation of symbols, 1, 1'...Inner coated steel pipe, 2,
2'...Annular body, 3,3'...Pipe fitting, 23,2
3'... Upright part, 121... Inclined surface, 241,2
41'...Slope part.

Claims (1)

[Scope of utility model registration request] An inner-coated steel pipe in which the inner circumferential surface of the end of the steel pipe is formed into an inclined surface whose diameter gradually increases toward the opening edge, and the inner circumferential surface of the steel pipe and the inclined surface are coated with thermoplastic resin, etc. 1. A tube end portion of an internally coated steel tube, characterized in that the end is crowned with a corrosion-resistant annular body that covers at least the tube end surface and the inclined surface coated with a thermoplastic resin or the like.